documentation: add some internals documentation about bid merge This is an important algorithm that was only documented on the wiki so far. Some update to the algorithm (and associated doc) is to expected in the future since the bid merge algorithm is bug-ridden when it comes to file deletion comes to play. Differential Revision: https://phab.mercurial-scm.org/D8711

cmdserver: document message-encodings and channel output options While writing the previous patch, I noticed these options are undocumented. In my testing, a separate status/error message channel works well in GUI frontend as we no longer have to sort out data and message from mixed outputs. So let's mark it as not experimental.

cmdserver: add option to not exit from message loop on SIGINT Sending SIGINT to server is the only way to interrupt a command running in command-server process. SIGINT will be caught at dispatch.dispatch() if we're lucky. Otherwise it will terminate the serer process. This is fundamentally unreliable as signals are delivered asynchronously. "cmdserver.shutdown-on-interrupt=False" mitigate the issue by making the server basically block SIGINT.

pycompat: remove pycompat.{stdin,stdout,stderr} All users have been changed to use procutil.{stdin,stdout,stderr}, which provide consistent behavior across platforms and Python versions.

pycompat: change users of pycompat.{stdin,stdout,stderr} to use procutil.std* On Python 3, pycompat.{stdin,stdout,stderr} are usually block-buffered even if connected to a TTY. procutil.{stdin,stdout,stderr} provide consistent behavior across platforms and Python versions.

hgignore: add mypy cache files Differential Revision: https://phab.mercurial-scm.org/D8692

revlog: avoid hard-coded hash sizes Differential Revision: https://phab.mercurial-scm.org/D8683

test: restore expected output in test-persistent-nodemap.t The merge 78cafd48b9b2 had a small error and wrongly dropped the output updated from one side of the merge. This changeset re-install it. Differential Revision: https://phab.mercurial-scm.org/D8678

heptapod-ci: build rhg before tests run Differential Revision: https://phab.mercurial-scm.org/D8682

rhg: add a limited `rhg root` subcommand Clap has been choosen for argument parsing for the following reasons: - it's a wildly used and maintained crate - it can deal with OS encoding making it suitable for any encoding - it supports nonambiguous prefix matching as already available in hg - it will soon allow for structopts-style declarative pattern instead of the currently used builder pattern Differential Revision: https://phab.mercurial-scm.org/D8613

rhg: add RootCommand using hg-core FindRoot operation to prepare `hg root` The println macro is not used to avoid string usage. Dealing only with bytes allows us to be compatible with any encoding and not just UTF8. Later on, format macro will be made to have more readable code. Differential Revision: https://phab.mercurial-scm.org/D8612

archival: abort if compression method is unavailable `tarfile.CompressionError` is documented to be the "exception for unavailable compression methods". Also, make tests conditional on whether the lzma module is available or not.